Daily aspirin - More benefit than risk?

Many people take a low dose of aspirin every day to lower their risk of a further heart attack or stroke, or if they have a high risk of either.

While the anticipated benefit is a lower chance of vascular disease, taking daily aspirin is not without danger: for instance it raises the risk of internal bleeding. Hence the important need to discuss beforehand with the doctor, "In my case, doc, should I be taking daily aspirin?"

But this week, the publication of three studies in The Lancet, has added a new benefit to the equation: cancer prevention, and stirred up the pros and cons debate.

In those studies, Professor Peter Rothwell of Oxford University in the UK, a world expert on aspirin, and colleagues, confirm that for people in middle age, a daily dose of aspirin can cut the risk of developing several cancers, with effects starting after only two to three years rather than the ten or so previously thought.

Moreover, they propose that treatment with daily aspirin may also prevent an existing, localized cancer from spreading to other parts of the body, which Rothwell says is just as important to know about, since that's when cancer becomes deadly.

If you follow their reasoning, we appear to have reached a crucial point in the debate: on the one hand we have the benefit that aspirin can reduce cancer, stroke and heart attacks, which are much more likely to lead to disability or death, and on the other, we have the risk of internal bleeding, which is less harmful than those diseases.

Such arguments cause more people, even those presently enjoying good health, to ask the question: "Should I be taking aspirin every day?"

But, although Rothwell and colleagues present compelling evidence, despite some limitations, their papers do not necessarily furnish a clear answer to that question.

Nevertheless, the balance of the pros and cons may alter in the light of their evidence, because not only does low dose aspirin therapy appear to increase the pros, it may also reduce the cons, in that the researchers found the risk of internal bleeding reduced with time.

Plus, the new studies also raise a thorny public health question, similar to that surrounding cholesterol-busters, should health authorities consider recommending routine use of aspirin for cancer prevention?

This was the subject of a commentary published in the same issue of the The Lancet. Here, Andrew T Chan and Nancy R Cook of Brigham and Women's Hospital, Harvard Medical School, Boston, suggest that on balance, we are not ready to recommend aspirin for cancer prevention.

One reason is that the Rothwell studies did not include data from the largest randomized trials in primary prevention, the Women's Health Study (WHS), and the Physicians' Health Study (PHS), where subjects took aspirin every other day.

"Also, despite a convincing case that the vascular and anticancer benefits of aspirin outweigh the harms of major extracranial bleeding, these analyses do not account for less serious adverse effects on quality of life, such as less severe bleeding," they add.

However, Chan and Cook acknowledge that as we await results of additional trials, and the longer term follow up of the WHS and PHS, the Rothwell studies do move us a "step closer to broadening recommendations for aspirin use".

At the very least, it means future evidence-based guidelines cannot ignore the use of aspirin for prevention of vascular disease in isolation from cancer prevention, they conclude.

Other authorities have also been quick to respond to the new studies. In the UK, the NHS's answer to the question "Should I start taking aspirin?" is:

"Overall, aspirin is a highly effective medical treatment when used appropriately, but it is not yet a drug that should be taken unsupervised on a daily basis, even at low doses."

They, like Chan and Cook, say that while the Rothwell studies "provide compelling evidence, taking aspirin is not yet recommended to prevent cancer and people should not start taking it daily as a precautionary measure."

For healthy people considering taking daily aspirin, they have this message:

"Given that the potential risks could outweigh any benefits, it is not currently advised that healthy people with no risk factors for cardiovascular disease take aspirin to prevent possible cardiovascular events such as heart attack and stroke."

They also say the evidence for taking aspirin purely to prevent cancer or to treat it is "even less substantial than for blood thinning", and urge "we cannot be sure that the potential benefits are not outweighed by the known risks".

The reason aspirin is prescribed in a small daily dose as a means to lower the risk of heart attack or stroke, is because of the effect it has on the clotting action of platelets in the bloodstream.

When we bleed, platelets in the blood build up at the site of the wound, forming a plug that stops further blood loss.

But this clotting can also happen inside blood vessels, such as when a fatty deposit in a narrow artery bursts. At the site of the burst, blood platelets clump into a clot that can block the artery and stop blood flow to the brain or heart, resulting in a stroke or heart attack.

Aspirin reduces the ability of the platelets to clump, thereby lowering the risk of having a heart attack or stroke.

In the UK, for example, aspirin is prescribed as a blood-thinner to reduce the risk of clots. The treatment comprises a small daily dose, often around 75mg (a typical aspirin painkilling tablet has about 300mg of aspirin).

But the downside to this anti-clotting benefit, is that aspirin can also cause serious harm, the best known of these being the small but important increased risk of stomach irritation and bleeding.

And, ironically, while daily aspirin can help prevent a clot-related (ischemic) stroke, it may actually increase the risk of a bleeding (hemorrhagic) stroke.

Although aspirin's risk-reduction benefits are different between men and women (and among women, it also depends on age), the risk of bleeding with daily aspirin is about the same in both sexes.

The risk of bleeding also tends to be higher in older people, those with a history of stomach ulcers, and people already taking medication or who have conditions that increase the risk of bleeding.

Daily aspirin use also increases the risk of developing a stomach ulcer. And, for anyone with a bleeding ulcer, taking aspirin will cause it to bleed more, perhaps to a life-threatening extent, say experts at the Mayo Clinic in the US.

People with asthma can also experience breathing problems with aspirin.

Other side effects of taking aspirin include nausea and indigestion, ringing in the ears (tinnitus) and hearing loss. And some people can have an allergic reaction.

Aspirin may double the chances of survival for patients with gastrointestinal cancers, according to the results of a new study recently presented at the 2015 European Cancer Congress in Vienna, Austria.

Taking low-dose aspirin daily could help women become pregnant, particularly those who have previously miscarried. This is according to new research presented at the American Society of Reproductive Medicine Annual Meeting in Baltimore, MD.

For some patients, it is worth risking the adverse effects of a regular aspirin dose in order to reduce the chance of cardiovascular disease and colorectal cancer, says research published in the Annals of Internal Medicine.

It has been hailed a "wonder drug" because of its numerous health benefits, and now, a new study provides further evidence that aspirin may help in the fight against cancer.

Aspirin recommendations

Before you take aspirin, even as a pain reliever, experts generally recommend that you talk to your doctor or pharmacist if you are pregnant, trying to conceive or are breastfeeding.

The same goes for people with a blood disorder, a stomach ulcer, who suffer from asthma, have high blood pressure, kidney or liver problems, or have allergic reactions to any drugs.

It is also important to tell your doctor what other medications or supplements you are taking. Even if you take aspirin with ibuprofen, it reduces the benefits of the aspirin. And taking aspirin with other anti-clotting agents, such as warfarin, could also greatly increase your risk of bleeding.

If you are on daily aspirin and need surgery or dental work, it is important you tell your surgeon or dentist what dose you are on, so they can minimize the risk of excessive bleeding during the procedure.

The US Food and Drug Administration (FDA) also warns those who take aspirin regularly to limit their alcohol intake, because that can have an additional blood-thinning effect, and raises the risk of upset stomach.

The Mayo Clinic suggest if you are on daily aspirin, you should limit your alcohol consumption to one drink or less per day if you are a woman, or two drink or less if you are a man.

Another point they make, is that stopping daily aspirin therapy may be unsafe: there is a rebound effect that can trigger a blood clot and cause a heart attack or stroke. It is important to talk with your doctor first before you make any changes or stop your daily dose.

Aspirin should not be given to children under 16 because of the risk of triggering a rare but dangerous condition known as Reyes syndrome, which is why in the UK it has been removed as an ingredient from all child and baby medicines.

Many experts would also advise those thinking about taking daily aspirin as a way to cut cancer risk, to consider there are many other, less harmful lifestyle changes that can also make a difference: such as giving up smoking, following a healthy diet, limiting alcohol intake, keeping to a normal weight, and taking regular exercise.

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Comments(19)

Maybe this aspirin a day is really only masking other bad habits in people's lives that if they eliminated in the first place they would all lower their risks. Fast food, or any restaurant purchased food, bad water, plastic food containers, drinks other then water, alcohol, household contaminates, etc.

I agree daily aspirin has many primary prevention benefits for heart disease, stroke etc, but I read in an article that aspirin over a prolonged period of time increases serum uric acid levels which is related to progressive atherosclerosis. My question is, aspirin is a drug known to reduce/prevent vascular disease, how much does elevated serum uric acid levels hinder the efficacy of the drug and its core principle as a primary prevention of vascular disease?

http://www.ncbi.nlm.nih.gov/pubmed/10643705 is the study on "The effect of mini-dose aspirin on renal function and uric acid handling in elderly patients." Their conclusion is that "Mini-dose aspirin, even at a dosage of 75 mg/day, caused significant changes in renal function and UA handling within 1 week in a group of elderly inpatients, mainly in those with preexisting hypoalbuminemia." So no idea about it's impact on Cardiovascular risk but each persons risks need to be individually assessed by a doctor before starting on aspirin.

After many,many articles on aspirin, few mention the importance of taking only enteric coated aspirin.
I would not consider taking plain aspirin on a daily basis because of the effect on the stomach lining. The enteric coating allows the aspirin to pass through the stomach and break down in the intestine and be absorbed.

The same is try with fish oil. The enteric coated fish oil allows the oil to be absorbed in the intestine without being affected by the acids in the stomach.

I had an physically active job and life style. But I've been taking a daily aspirin for 10 years ever since a heart in 2002. I also take a fish oil capsule and a small dosage mutivitamin multimineral. The later I have taken for 35+ years. Have they all helped?, well I am still upright and mobile, so they don't seem to have hurt. Bottom line is that sooner or later everyone dies, but death certificates never seem to list "excellent health" as the cause.

The odd part is that many athletes swear by steroids and many casual users love their "recreational drugs" and alcohol in all it's forms..... but aspirin gets the rap.

So eat moderately but well, exercise, don't drive carelessly and look both ways before you cross the street.....and you may reach elderhood with all it's aches and pains and short term life goals.

I cannot believe the warnings against aspirin when the benefits are so pronounced. Fact my wife who has no family history of strokes was put on aspirin by me for 3 years before she had a stroke. The specialist said the aspirin saved her far a far worse problem. My 22 YO daughter is on daily aspirin since she was 18 because we have a family history of heart problems. She had a stroke at 21 and a blood clots on the lungs which could have proven fatal without the aspirin. I believe 175mg per day is essential and if you have stomach problems take it with food.

My father, grandfather and uncle all died of heart attacks in their mid-fifties; my 3 younger siblings all have serious heart issues. I am 60 next birthday and playing serious squash. Been on 150 mg aspirin for 15 years. For heaven's sake: if we may take 2400 mg of aspirin per day for 10 days before seeing a doctor, 75 mg per day in a healthy person is to be seriously recommended.

Sure, clear it with the doctor, and then just DO it (always with food). By, the way, the benefits are not only cancer, heart attack and stroke; dementia (as a vascular disease affecting the brain) is also addressed. And if your doctor is vague about it all, get another doctor, soon!

Perhaps when taking pain killers we should use a variety - so one month use one type and the next month use a different one perhaps??? On the other hand i've stopped taking ibruprofen and aspirin for time of the month as they both increase bleeding... lol what to do for the best... no idea...

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